qtest: add qtest_server_send abstraction

qtest_server_send is a function pointer specifying the handler used to
transmit data to the qtest client. In the standard configuration, this
calls the CharBackend handler, but now it is possible for other types of
handlers, e.g direct-function calls if the qtest client and server
exist within the same process (inproc)

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-id: 20200220041118.23264-6-alxndr@bu.edu
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

2 files changed, 19 insertions, 2 deletions

diff --git a/include/sysemu/qtest.h b/include/sysemu/qtest.h
index 5ed09c80b1..e2f1047fd7 100644
--- a/include/sysemu/qtest.h
+++ b/include/sysemu/qtest.h
@@ -26,4 +26,7 @@ bool qtest_driver(void);
 
 void qtest_server_init(const char *qtest_chrdev, const char *qtest_log, Error **errp);
 
+void qtest_server_set_send_handler(void (*send)(void *, const char *),
+                                 void *opaque);
+
 #endif
diff --git a/qtest.c b/qtest.c
index 587dcbb4b5..8a4ba59828 100644
--- a/qtest.c
+++ b/qtest.c
@@ -43,6 +43,8 @@ static GString *inbuf;
 static int irq_levels[MAX_IRQ];
 static qemu_timeval start_time;
 static bool qtest_opened;
+static void (*qtest_server_send)(void*, const char*);
+static void *qtest_server_send_opaque;
 
 #define FMT_timeval "%ld.%06ld"
 
@@ -229,8 +231,10 @@ static void GCC_FMT_ATTR(1, 2) qtest_log_send(const char *fmt, ...)
     va_end(ap);
 }
 
-static void do_qtest_send(CharBackend *chr, const char *str, size_t len)
+static void qtest_server_char_be_send(void *opaque, const char *str)
 {
+    size_t len = strlen(str);
+    CharBackend* chr = (CharBackend *)opaque;
     qemu_chr_fe_write_all(chr, (uint8_t *)str, len);
     if (qtest_log_fp && qtest_opened) {
         fprintf(qtest_log_fp, "%s", str);
@@ -239,7 +243,7 @@ static void do_qtest_send(CharBackend *chr, const char *str, size_t len)
 
 static void qtest_send(CharBackend *chr, const char *str)
 {
-    do_qtest_send(chr, str, strlen(str));
+    qtest_server_send(qtest_server_send_opaque, str);
 }
 
 static void GCC_FMT_ATTR(2, 3) qtest_sendf(CharBackend *chr,
@@ -784,6 +788,16 @@ void qtest_server_init(const char *qtest_chrdev, const char *qtest_log, Error **
     qemu_chr_fe_set_echo(&qtest_chr, true);
 
     inbuf = g_string_new("");
+
+    if (!qtest_server_send) {
+        qtest_server_set_send_handler(qtest_server_char_be_send, &qtest_chr);
+    }
+}
+
+void qtest_server_set_send_handler(void (*send)(void*, const char*), void *opaque)
+{
+    qtest_server_send = send;
+    qtest_server_send_opaque = opaque;
 }
 
 bool qtest_driver(void)